Dioxins & Furans
TCDD · PCDD/PCDF
What it is
A family of chlorinated byproducts, never made on purpose. They form when chlorine meets organic matter, including during the bleaching of wood pulp and rayon. TCDD is the most toxic member and the reference compound.
In this product: None. They are an unwanted contaminant of chlorine-bleached fiber, not an added ingredient.
Dose & route, what actually matters
The route is what makes a trace worth naming: vaginal mucosa absorbs far more readily than skin, the contact is direct, and use spans roughly 12,000 tampons over a lifetime. Even so, FDA and independent testing put current tampon dioxin well below the dioxin you get from food. Total-chlorine-free (TCF) products carry essentially none.
EUROPEAN UNION
TCDD is classified Carc. 1A (known human carcinogen) under EU CLP Regulation (EC) No 1272/2008. The EU drove much of the move to chlorine-free pulp bleaching.
UNITED STATES
EPA classifies dioxins as known human carcinogens with no safe threshold. The FDA asks tampon makers to monitor dioxin but does not publish the results.
The evidence
IARC classifies 2,3,7,8-TCDD as carcinogenic to humans (Group 1), based on mechanism and animal evidence with limited human data.
regulatory · 1997 · source
Bleaching wood pulp into rayon once produced trace dioxins in tampons; the method was replaced with chlorine-free bleaching in the late 1990s, and the FDA states tampon dioxin exposure is many times lower than ordinary dietary exposure.
review · 2024 · source
California Prop 65: 2,3,7,8-TCDD is listed under California Prop 65 as a carcinogen.
How to avoid it
Choose tampons and pads labelled chlorine-free or totally chlorine-free (TCF), or 100% organic cotton, which skip the chlorine-bleaching step that creates dioxins in the first place.
Editorial analysis of publicly available regulatory and peer-reviewed sources. Not medical advice. We name our evidence and link it, including when an ingredient is fine.